Binders for non-woven materials based on vinyl acetate copolymers, are known. Such binders, among others, increase the mechanical strength, the wet tear strength and the resistance to dry cleaning and impart a pleasant handle to the non-woven materials produced therewith. When punching sheet-like articles, particularly of circular form, from a continuous web of non-woven materials substantial amounts of scrap may be produced, which, because of the binder content, cannot be recycled to the non-woven material manufacturing process. To be able to do so, it would be necessary again to remove the binder from the non-woven material.
Copolymers which contain carboxyl groups and are soluble in alkali are known. However, such polymers are so sensitive to water that their use as binders for the manufacture of non-woven materials having good wet tear strength is not possible.
The use of alkali-soluble polymeric substances as textile glues (sizes) has been known for a substantial time. As a result of the use of water-jet looms when processing sized yarns, the additional need for sufficient water resistance of these alkali-soluble sizes arose. In German Offenlegungsschrift (DOS) No. 2,162,285, this object was achieved by using, as textile glues, poly-(vinyl acetate/dialkyl maleate/acrylic acid) sizes, dimethyl maleate and/or diethyl maleate being employed as the dialkyl maleate. It is known that such polymers meet the standards to which the water resistance of a yarn sized therewith has to conform when used for water-jet weaving, but they cannot be used as alkali-elutable binders for non-woven materials having good wet tear strength.